Friday, April 7, 2017

Bleached staghorn coral
on the Great Barrier Reef
between Townsville and Cairns, March 2017, Credit: Bette Willis, Source: JCU

Some years ago I visited the Great Barrier Reef offshore from the resort town of Port Douglas. It was a magical experience (and I think the only time I've scuba dived in the ocean). Later I had the privilege of swimming over part of the Great Barrier Reef again from the seas around the Whitsundays, staying at Airlie Beach. Apart from some snorkelling over coral reefs in a few other places, such as Bali, and doing some work with the fishing industry, I know very little about coral reefs. Any knowledge I do have is thanks to experts.

What I do know is that coral reefs are extremely critical ecosystems for maintaining marine life and protecting coastal environments, and for all sorts of human activities too, such as fishing, tourism and more.

I also know that our actions are killing many corals and even entire reefs.

Although I've written about them in the past, I'm reluctant to delve too deeply into a topic as complex and specialised as coral reefs for risk of giving wrong information. However the sort of nonsense that you read by deniers and disinformers, who seem to want to kill the reefs off as quickly as possible, has prompted me again. That plus the fact that governments in Australia (the Australian Government and the Queensland Government), a suspect coal company from India, and less prominent players are doing all they can to speed up the death of the Great Barrier Reef by giving our hard earned money, plus permits, for Adani to mine coal and wreck the reef (and use up our precious water).

On top of all that, the Great Barrier Reef is suffering another bleaching event this year, hot on the heels of the worst mass bleaching ever that happened last year.

What finally got me going was an article at WUWT by Jim Steele, in which he tried to tell his readers that the 2016 coral bleaching wasn't really widespread (it was the worst ever), and was caused by any of a whole number of different reasons he offered up, except the real cause - excessive ocean heat. Jim Steele's a global warming denier, in case you've not heard of him.

See update below, too.
Because of all this, I've read more and made contact with a couple of experts and this article is the result. All errors are mine - so if you see some, let me know and I'll correct them.

We are the biggest threat to coral reefs

The biggest threat to coral reefs is us. People. Human activity.

The causes of the present-day demise of coral reefs are varied. One of the biggest causes is global warming. This is having both direct and indirect effects on coral reefs.

Coral bleaching

Mass bleaching is causing huge damage to coral reefs around the world. There was a recent paper in Nature by Professor Terry Hughes and a team of scientists. Corals are marine animals that have a symbiotic relationship with particular algae. They rely on each other to live. The authors of the paper explained how heat stress disrupts this symbiotic relationship and this is evident when corals lose their colour - hence the term "bleaching". The authors wrote:

Bleached corals are physiologically damaged, and prolonged bleaching often leads to high levels of coral mortality.

That's it in a nutshell. Bleached corals don't necessarily die. They are sick, and sometimes recover. Depending on the severity of an event, or how often it's repeated, and other factors, corals and coral reefs can die - or they may recover.

Other factors affecting corals

Corals can be damaged and die from causes other than bleaching. There was a paper recently in Biogeosciences that was about how a drop in sea level caused mortality in shallow coral reefs in Bunaken Island in North Sulawesi. That is, not bleaching but death. The authors stated (my emphasis and paras):

This study reports coral mortality in Indonesia after an El Niño-induced sea level fall. The fact that sea level fall, or extremely low tides, induces coral mortality is not new, but this study demonstrates that through rapid sea level fall, the 2015–2016 El Niño has impacted Indonesian shallow coral reefs well before high sea surface temperature could trigger any coral bleaching. Sea level fall appears as a major mortality factor for Bunaken Island in North Sulawesi, and altimetry suggests similar impact throughout Indonesia.

Our findings confirm that El Niño impacts are multiple and the different processes need to be understood for an accurate diagnostic of the vulnerability of Indonesian coral reefs to climate disturbances. This study also illustrates how to monitor local sea level to interpret changes in a particular coastal location.

The authors of the Indonesian study point to a range of factors that can adversely affect corals. In addition to a rapid fall in sea level, the authors list things corals can be seriously damaged by (I've added more information in italics):

storms, which harm but can also help - e.g. Winston saved the southern GBR last year. The current bleaching might not have been as bad if Debbie had arrived sooner

sea level rise, when it rises more quickly than a reef build up, etc.

Terry Hughes' on coral reefs TedTalk

In the talk below, Terry Hughes talks about the damage to reefs and yet how he retains some optimism that we can save the world's coral reefs. He also describes the research that he reported in his Nature paper. It's less than 15 minutes long. If you've time and even if you're short of time, it's well worth watching.

Note how Professor Hughes distinguishes between the time needed for different corals to recover, and the risk of more bleaching events preventing some from being able to do so. (about 10 minutes in). "If you lose a 100 year old coral, you cannot replace it in a few years."

The pseudo-science nonsense from climate disinformer, Jim Steele

You may have come across Jim Steele before. He's a wannabe scientist who has never published any scientific research papers as far as I can tell. He's retired now, I believe, after working part-time as a manager of a field station for a college in California, where he organised nature walks or something. These days he spends his time writing disinformation for WUWT so he can promote his vanity-published denier book, and conducting personal vendettas on a small number of individual scientists. He's seems to be very jealous of their success, and just as clearly is a scientific ignoramus with a history of blatant lying.

This week Anthony Watts, who runs a climate conspiracy blog WUWT, chose to publish another article by Jim Steele (archived here). In this one Jim did his usual misrepresentation of science, mixed with his denial of global warming.

Remember how the second paper I referred above to was about mortality (not bleaching) from sea level fall? Well, Jim Steele started off badly, with a headline "Falling Sea Level: The Critical Factor in 2016 Great Barrier Reef Bleaching!". Jim wrote:

The paper he referred to is about coral mortality on a reef shelf from a sudden drop in sea level. The authors didn't mention the word "bleaching" except in references to mass bleaching events from marine heat stress. As the authors state in the abstract, the rapid fall in sea level resulted in substantial death of the corals "likely by higher daily aerial exposure, at least during low tide period".

Still on page one of the paper, the authors wrote about what happens when corals are heat stressed. The symbiosis between the coral and the algae is disrupted and the coral turns white:

El Niño increases temperature in several coral reef regions and induces zooxanthellae expulsion from the coral polyp, resulting in a coral colony looking white, hence “bleaching”. If the situation persists the coral colony eventually dies.

…Thus, it is assumed that coral bleaching induced by ocean warming will be the main culprit if post-El Niño surveys report coral mortalities.

Jim didn't mention that part of the paper. How could he have missed it?

What the authors were focused on in their research was what happened in the lead up to the severe El Nino temperatures of 2016 (but before the hottest temperatures). They attributed the coral deaths to a severe drop in sea level. Below is Figure 1. from Ampou17, which shows pictures of the coral on Bukanen reef before and after this extreme drop.

Figure 1 | Bunaken reef flats. (a) Close-up of one Heliopora coerula colony with clear tissue mortality on the upper part of the colonies; (b) same for a Porites lutea colony; (c) reef flat Porites colonies observed at low spring tide in May 2014. Even partially above water a few hours per month in similar conditions, the entire colonies were alive. (d) A living Heliopora coerula (blue coral) community in 2015 in a keep-up position relative to mean low sea level, with almost all the space occupied by corals. In that case, a 15 cm sea level fall will impact most of the reef flat. (e–h) Before–after comparison of coral status for colonies visible in (c). In (e), healthy Porites lutea (yellow and pink massive corals) reef flat colonies in May 2014, observed at low spring tide. The upper part of colonies is above water, yet healthy; (f) same colonies in February 2016. The white lines visualize tissue mortality limit. Large Porites colonies (P1, P2) at low tide levels in 2014 are affected, while lower colonies (P3) are not. (g) P1 colony in 2014. (h) Viewed from another angle, the P1 colony in February 2016. (i) Reef flat community with scattered Heliopora colonies in February 2016, with tissue mortality and algal turf overgrowth.

Other causes of coral damage and death

As you can see from the above, in particular regions different factors can cause coral reef damage. At the very local level, bleaching response and coral mortality can be from various causes. For example, in a short article in Coral Reefs (2006), Leggat et al described coral mortality in a section of the Great Barrier Reef on Heron Island, back in 2005. They said how it was probably caused by high winds combined with aerial exposure, noting that the maximum water temperatures at the time were not sufficient by themselves to cause bleaching. Corals on the eastern side weren't affected. The authors wrote:

Although solar radiation cannot be ruled out in the present case, the direction of the bleaching (west-north-west) is more consistent with the observed wind direction, rather than the sun azimuth (west-south-west) during the preceding low-tide periods. It appears that the stress of high winds and aerial exposure, possibly together with the sub-bleaching water temperature, prompted the observed bleaching pattern.

Compare Figure 2 above with the spatial pattern of temperature stress, recorded as degree heating weeks (DHW). As you can see, in each bleaching event (1998, 2002 and 2016), the greatest coral damage was where there was the greatest heat stress.

Huge increase in Degree Heating Weeks

Degree Heating Weeks (DHW) are a bit complicated. The concept is best described in some detail in Liu et al (2003) in EOS. What DHW shows is how much heat stress has accumulated in an area. It is measured as HotSpot anomalies, which are departures from the "climatological mean temperature of the climatological hottest month". That means it is region specific, though it's not like a normal sea surface temperature anomaly (which uses a different mean as a baseline). Essentially it is an indicator of the departure from the bleaching temperature threshold for coral reefs. The bigger the departure and the longer the duration the greater the risk of severe damage to the coral. From Liu03:

Field observations (most of which are subjective measurements presented as informal reports) with coincident satellite data are only available for a limited number of years; these observations indicate that there is a correlation with bleached corals when DHW values of 4.0 have been reached. By the time DHW values reach 8.0, widespread bleaching is likely and some mortality can be expected.

Have a look at the charts below, from Hughes17, showing DHW for each of the three bleaching events. In 2002 there were a lot of reefs where DHW values were greater than 8.0. In 2016 there were many more:

Jim Steele and his pseudo-science Gish gallop

If you are a discerning reader, you'll immediately see that Jim Steele's article at WUWT is suspect. He spends time trying to discredit some experts and misrepresents or cherry-picks from others. He gives no solid evidence for his claim that falling sea levels were responsible for bleaching over the entirety of the bleached areas in 2016 (or at any time). (This is an area the size of Italy that we're talking about, not a lone reef on the edge of a small tropical island.) He hits his readers with every notion he can think of as an alternative to the actual cause of the mass coral bleachings described in Hughes17.

Aerial and underwater surveys

Hughes17 is based on data collected from extensive aerial and underwater surveys. Jim Steele implies that the researchers of Hughes17 relied only on aerial surveys, ignoring the fact that the scientists assessed the accuracy of the scores applied from the aerial surveys by ground-truthing. As the authors wrote:

To ground-truth the accuracy of aerial scores of bleaching on the Great Barrier Reef (Fig. 1a), we conducted in-water surveys on 104 reefs during March and April 2016 (Extended Data Fig. 5). We also measured differential species responses (winners versus losers; Fig. 4) on 83 reefs, spanning the 1,200-km-long central and northern Great Barrier Reef, from 10–19° S. We surveyed two sites per reef, using five 10 × 1 m belt transects placed on the reef crest at a depth of 2 m at each site. Observers identified and counted each coral colony and recorded a categorical bleaching score for each individual: 1, no bleaching; 2, pale; 3, 1–50% bleached; 4, 51–99% bleached; 5, 100% bleached; 6, bleached and recently dead. The site-level amount of bleaching for each taxon in Fig. 4 is the sum of categories 2–5. The number of colonies assessed was 58,414. A similar standardized protocol was used to measure amounts of bleaching for the Coral Sea, on sub-tropical reefs south of the Great Barrier Reef, and across 18° of latitude along the west coast of Australia (Fig. 1g).

If only disinformers were as particular.

Anything but hot water

When Jim wrote the following Gish gallop of suggestions, he shows no logic, and wants the bleaching (that he doesn't believe in) to be anything but hot water. He wrote:

Aerial surveys, on which Hughes 2017 based their analyses, cannot discriminate between the various causes of bleaching. To determine the cause of coral mortality, careful examination of bleached coral by divers is required to distinguish whether bleached coral were the result of storms, crown-of-thorns attacks, disease, aerial exposure during low tides, or anomalously warmer ocean waters.

Is he really suggesting that all these different events came to pass at exactly the same time as the excessively hot waters, and that it was the above events, not hot water, that caused the massive bleaching, covering umpteen thousand square kilometres of reef?

Unlike the researchers, Jim provides not a jot or hint that he has any evidence to support his implied claim, apart from showing a chart of sea level in one single spot off the coast of northern Queenland, Lizard Island, which only goes, with gaps, from 1960 to the end of 2015. (Here's a blog article from March 2016 from the Lizard Island Research Centre, about the coral bleaching there.) Jim's chart doesn't show that the 2015 sea level was any lower than it's been in the past, when there was no bleaching.

I did ask Terry Hughes about this, and his response, in part, was:

We also showed that the amount of bleaching measured below water ranged from 0-100%, and was tightly correlated with DHW (Figure 3). If sea level was responsible why didn’t cooler reefs also bleach? We found bleaching down to 40m which can’t be explained by any tidal anomaly.

Below is the Figure 3 that Dr Hughes mentioned, showing the relationship between heat exposure and bleaching in March/April 2016:

It's not just the correlation of bleaching and DHW, I expect most of you will have picked up this next point, too. In the study that Jim Steele looked at in which aerial exposure caused coral mortality, the coral at depth wasn't harmed. Jim Steele even noted that in his article. (In fact, the scientists unsurprisingly reported that many corals in that region are often exposed to the air without harm. It was the extent of exposure that made the difference in 2015.) So how can he possibly try to argue that reefs at 40 metres below the sea surface were killed by low sea level rather than the obvious culprit - excessive exposure to hot water?

Interestingly, in an article in the Guardian today, it was stated that a couple of groups have suggested to the Australian Government that cold water should be pushed onto a couple of reefs to protect them from coral bleaching. Most experts didn't much like the idea for various reasons, but it does mean that people accept the evidence that bleaching is caused by excessively warm water.

It's El Nino - good for Jim - he's partly right

After trying that hotch potch of notions, Jim shifted to El Nino as the cause. He's correct to a point. However it was El Nino on top of global warming. There have been El Ninos for centuries and it's only in recent times that they've heated up the oceans so much that they've caused mass bleaching. The other point is that there is no El Nino right now, yet the Great Barrier Reef is suffering another hit of coral bleaching this year, 2017.

Global scale or "patchy"?

Hughes 2017 wanted to emphasize GBR bleaching as a “global-scale event” in keeping with his greenhouse gas/global warming attribution, but bleaching and mortality was patchy on both local and regional scales.

He's not serious, is he? The 2016 mass bleaching was the worst ever. Perhaps by "patchy" Jim meant that there were some reefs somewhere in the tropics that escaped mass bleaching.

The authors of Hughes17 reported that in 2016, the proportion of extreme bleaching in the Great Barrier Reef (more than 60% of corals bleached) was four times higher that the mass bleachings of 1998 and 2002. They wrote that in 2016:

...only 8.9% of 1,156 surveyed reefs escaped with no bleaching, compared to 42.4% of 631 reefs in 2002 and 44.7% of 638 in 1998. The cumulative, combined footprint of all three major bleaching events now covers almost the entire Great Barrier Reef Marine Park, with the exception of southern, offshore reefs (Fig. 1d).

Jim added this next bit, which was him practicing deception or lack of comprehension:

The lack of mortality in 2016 across the southern and Central GBR, was explained as a result of the cooling effects of tropical storm Winston, but that does not explain why individual reefs in those regions have not bleached at all, while others bleached only once, and still others bleached twice or three times since 1998.

Jim should have looked at Figure 1 in the paper, which illustrates how heat stress affected different areas of the Great Barrier Reef at different times (see Figures 2, 3 and 4 above, especially Figure 3 that shows the lack of heat stress in the southern portion in 2016).

Cherry-picking and more

There's more. After arguing that mass bleaching probably isn't getting worse because of hotter seas as the world warms, Jim cites different studies, but ignores the parts where the authors talk about mass bleaching from heat stress. One of these is Wooldridge13, where the author is explaining the mechanism that causes mass coral bleaching, would you believe. Jim should take note of the last sentence in Wooldridge13, which is (my emphasis):

Future testing and refinement of the ideas presented within this paper thus offers considerable hope for developing further insights into tack[l]ing the climate-induced demise of coral-algae symbioses and the reefs they construct.

Jim's Gish gallop continues into how it's not just sea level, crown of thorns, storms, disease, low tides - he next tosses into his mix of distractions high nutrient loading that caused the mass bleaching that Jim thinks didn't happen anyway. Sure - as Terry Hughes said in the video above, replacing bad water with good water will help, and all these these things affect coral, but they didn't all happen everywhere all over the tropics, in the same short time interval, just when the oceans happen to be excessively hot, and not at any other time. It's the heat stress that clearly caused the coral bleaching in the periods described in Hughes17.

Jim's real message - denying global warming

I won't bother with the rest of Jim's article, except this bit where he shows his underlying rejection of climate science, if not his motivation for rejecting science and the knowledge of experts. He wrote:

After perusing Hughes 2017, it was clear they had been led to incorrectly embrace the prevailing bias of CO2-induced catastrophic bleaching because they failed to address the fall in sea level before and during the 2016 El Niño, and likewise they failed to address how weather created by El Niños promotes clear skies and increased solar heating.

I dare any normal sane person (i.e. not a hard-core conspiracy theorising climate "hoax" crank) to read Hughes17 and not be convinced that mass bleaching is the result of excessive ocean heat, and that it is causing real and already has probably caused irrevocable damage to one of Australia's most precious resources.

I dare the same people to read Jim Steele's article and not be amazed at the red herrings, snide insinuations, pseudo-scientific crap, misdirection, misrepresentation, cherry-picking, and disinformation he's managed to cram into a single article. It is quite a challenge to wade through his diatribes and I don't recommend it. Jim is getting more practiced at diluting some good science with loads of pseudo-science, while rejecting the elephant in the room.

Weeping for a lost reef

Jim Steele claims he wept, which I expect is a snarky reference to a tweet by Terry Hughes, lead author of the Nature paper that Jim tried to trash:

Jim Steele isn't weeping. He is doing his utmost to kill coral reefs as quickly as he and his anti-environmental vandals can.

The experts in coral reef science are doing their best to save it. Unfortunately, as Terry Hughes said: "Now, tragically, the GBR is severely bleaching again in 2017 in regions that got too hot."

As a final note, the prestigious general science journal Nature included Professor Terry Hughes, as one of the top ten people who mattered in 2016. (I didn't see Jim Steele's name in the list.)

Update - an ethical issue

I've just been made aware that the Townsville Bulletin has unbelievably presented the crank denier nonsense of Jim Steele as being as credible, or more so, than rigorous science from the foremost coral experts in the world. So I've decided to add some from the email from one of the authors of Ampou17, whose work the Townsville Bulletin mentioned, hoping he doesn't mind.

I suggested: Your paper does not refute the work that has shown that excessive warmth of some duration can cause coral bleaching.

...we never contradict that bleaching can be caused by warming. It's silly to pretend otherwise....if someone is manipulating and transforming the content of paper to push his ideas, that's an ethical issue. I can just condemn this.

From the WUWT comments

Climate conspiracy wackos at WUWT only like articles that reassure them that the world isn't really warming. They don't care much about nature, and some despise it. The "thoughts" show no-one capable of critical thinking. None of them saw that Jim was jumping all over from one excuse to another trying to find a cause for mass bleaching that didn't involve heat. Nor that he dismissed the mass bleaching as pretty well inconsequential. If these people had their way there'd be no coral reefs at all.

jfpittman falls hook line and sinker for Jim's fib about Terry Hughes, nutrients and coral reefs, which I'm sure will cause Jim Steele some sadistic pleasure. See the video in the article above, when Dr Hughes talks about the bad things that people do to coral reefs reefs around the world. The very first item that he mentions is pollution, run-off from nutrients etc. (see it on YouTube at 1m38s). Disinformers are shameless. Their fans are stupid, gullible or disinformers pretending to be gullible - or maybe a combination of all three.

April 5, 2017 at 7:03 am
I used to read Nature when it was the publication likely to have analysis like Jim’s.It seems so strange to see the work on eutrophication and its impact on biomes discarded. It took a lot of effort to get governments around the world to recognize that improper discharge of waste could harm species diversification, and change the fundamental relationships in the ecological microsystems. Assuming, and by that assumption throwing away so much hard won science by a scientist, seems so much worse than anything a non scientist can do from ignorance or purposeful stubbornness.

Greg doesn't understand that Centres of Excellence in Australia is the collective name given to collaborative efforts involving scientists from multiple organisations, working in a particular field. Or maybe, like everyone at WUWT, he just hates knowledge.

April 5, 2017 at 9:04 am
” the ARC Centre of Excellence for Coral Reef Studies”
Yet another of these bullshit “Centres of Excellence”. Who are they trying to con ? If you were a centre of excellence you would not need to put it on the letter head. Do Yale and Harvard have to put “excellence” in their names? No, because they ARE centres of excellence not bullshit merchants trying to dress politics as science.

Peter Ridd is a known disinformer from JCU (remember Bob Carter, the devil rest his soul?), who is a mate of Jennifer Marohasey and belongs to a denier/disinfomer club. He is an unethical one at that, claiming that random un-named tourism operators, who have a vested interest, are more trustworthy than methodical, rigorous, scientific research from his much more highly esteemed professional colleague.

April 5, 2017 at 4:20 pm
Jim,
you may be interested that there was a mass mortality of mangroves in the Gulf of Carpentaria last year also caused in part by a temporary drop in sea level associated with El Nino. It was a huge event. see link below or I can send you the original paper.
I should add that I have looked at many of the videos of the bleaching taken from aircraft and it is difficult to see how the figures that Hughes presents are credible. In addition a parallel survey of GBR bleaching done by tourist operators indicated far lower levels than reported by Hughes team.
It looks like another example of results we cannot trust.
Peter Ridd
James Cook University

(Peter Ridd linked to an article at The Conversation, which was based on research published by CSIRO. Low sea level was considered a likely a factor with the mangrove die-off, but so was unprecedented high temperature and severe drought. Global warming again!)

DaveR is unable to read critically. He mistakenly thinks that Jim's multiple excuses to avoid ocean warming and mass bleaching are "hypothesis" based on data. They aren't. There is no meaningful data from Jim. It's just a Gish gallop of the type you see every day on denier blogs.

April 5, 2017 at 6:20 pm
Its always refreshing to see a scientific article which looks at the data first, and then makes hypotheses second. There is not a lot of that approach in the climate fraternity. It even more refreshing when that study explodes a dogma well past its use-by date.
On a scientific point, a 120m sea level rise in the last 20ky after the last ice age peak means that all current corals down to 120m didnt exist 20k years ago, and the shallower colonies are very young.
I have a feeling that corals dog the current sea level and live/die as MSL moves. Isotopic age studies on corals must be particularly illuminating.

Peter s says he has some sort of story he wants money for, but I don't know what it is. His next snorkelling holiday perhaps? I figure he thinks that the sun bleaches coral just like it bleaches the sheets on the clothes line. He's wrong.

April 5, 2017 at 9:11 pm
I have snorkeled out there twice and it is breathtaking as you dive down deeper. The GBR is a living thing. In ideal conditions the coral grows wider and higher until it gets close to the surface where it is exposed to the sun more often during low tide. Naturally its vivid colours will become bleached. But of course there is no funding in this sort of story.

ptolemy2 mistakenly thought that sea levels are falling. What a nutter. She or he probably thinks the world is cooling, too.

April 6, 2017 at 5:04 am
So sea level rise is levelling off and the Climagesterium is trying to conceal the fact.
This could get interesting.

The rate of rise has gone up to 3.4mm a year and despite the end of El Nino, it's still above the long term trend - from the CU Sea Level Research Group:

graphicconception expressed his thanks for all the "alternative causes", not caring that none of them were the primary cause of the mass bleachings last year or this year.

April 6, 2017 at 5:56 am
Excellent article. Duly bookmarked.
The information I think the public needs includes the alternative causes for a particular effect. The AGW fraternity are happy to push the “warming causes everything” approach. It is only when you have an idea of the other things besides warming that can have an effect that you can counter their arguments successfully. This article provided that information. Thank you.

The rest are no better, and simply demonstrate yet again that WUWTers are not capable of understanding science, unable to think or read critically, and willing to swallow anything they read on a denier blog as long as it pokes fun at real knowledge. And, of course, as long as it dismisses climate science as a "hoax".

127 comments:

I've seen this argument posed several times on sewers like CargoCult Etc.: where is the data demonstrating similar bleaching events did not happen in the past?

So I have snorkeled the shoreline of Magnetic Island and I have scubaed the GBR... also off Townsville. I cannot imagine that a coral bleaching event could go unnoticed along the shoreline of Magnetic Island (I believe it has been a resort sight for a very long time,) and I find it difficult to believe Australian fisherman and the various navies of the world could see, with no comment at all, a bleaching event on the GBR and not make some sort of comment.

Hi JCH, this might help answer their question. It's from 1993, but it is well-referenced, and has charts (pictures for the comic book readers). If anyone has more, please post them.

Mass coral mortalities in contemporary coral reef ecosystems have been reported in all major reef provinces since the 1870s (Stoddart 1969; Johannes 1975; Endean 1976; Pearson 1981; Brown 1987; Coffroth et al. 1990). Why, then, should the coral reef bleaching and mortality events of the 1980s command great concern? Probably, in large part, because the frequency and scale of bleaching disturbances are unprecedented in the scientific literature. For example, no less than 60 major "coral reef bleaching events" (Fig. 1 a) were reported over the 12 year period, 1979-1990 (Coffroth et al. 1990; Williams and BunkleyWilliams 1990; Glynn 1991), compared with 45 "mass coral mortalities" (Fig. 1 b, c) caused by various other disturbances. In contrast, only three bleaching events were reported among 63 mass coral mortality records during the preceding 103 years (1876--1979; Coffroth et al. 1990; see Fig. 1 caption for additional references).

In 1998 and 2006 severe bleaching occurred around the world, caused by warmer than average sea temperatures linked to El Niño events. These widescale events are known as “mass bleaching“. Until 1979 only 3 mass bleaching events had been recorded around the world. In 2002 alone, 400 events mass bleaching events were recorded (UNEP) and by 2008 mass bleaching had occured in every coral reef region of the world.

The problem here is that prior to 1980, there was no means to measure the global or even regional extent of coral bleaching events. There simply wasn't a means to correlate observations of bleaching in a coordinated way. Since the means to observe and measure have become accessible, it is hardly surprising that reporting is "unprecedented in the scientific literature". Obviously.

I'm guessing you are either very young, Brian, and aren't aware that there were communication mechanisms prior to networked computers. Either that or you're getting on in years and are suffering the old male syndrome that afflicts a minority of people, resulting in climate science denial.

Ah yes, if all else fails cry "straw man". But feel free to show us why "means to measure the global or even regional extent of coral bleaching events" prior to 1980 is absolutely crucial to the issue.

Brian's hypothesis, if I understand it, is that the seas in which the corals live have had super hot spells as hot and as widespread as last year (and this), and as frequently as recently, quite often in the past several hundred years, and have therefore suffered mass bleaching as often as they are suffering them now. I'd really like to see the data on which he bases his hypothesis.

How did the reefs manage to survive? How is it that there's no sign of these frequent mass coral bleaching events? How did all the fishers miss it? How did the seas get so hot without any impact on land or in the ocean that left a sign? What caused these extra hot spells in the ocean?

So Brian didn't try to answer my question. He admitted it was a fair question but he didn't deign to respond to it.

Instead he went with a generalised hypothetical that bore no proper relation to the issue, but which he could respond to. Umm, now what is doing that called? And what was he complaining of only a moment before?

So Brian, why do we have to have pre 1980s data? How do we need that in order to know if hotter temperatures kill coral or if global warming is happening, or if global warming makes things warmer? Or, well, what?

And the /sarc did, at least, elicit laughter from me. Given the shallowness of his response it had all the effect of watching a small child blow out their cheeks in an infantile pout.

I do recommend rereading his post with that in mind. At least then he provides some entertainment.

In your post above, and in your article, you assume that it is a FACT that current coral bleaching is (a) related to global warming, and therefore escalating in severity and intensity, and (b) that this will ultimately destroy the GBR.

Now we don't have direct observational evidence over time for either of these conclusions. They are logically inferred from the available evidence. There is nothing wrong with making a logical inference, but it should be called out, because without direct observational evidence there is room for doubt, and alternative hypothesis. That is my only point.

Now in anticipation of further accusations about me being a denier, because I apparently "doubt" the FACT that global warming is destroying the GBR,

(1) refer you to my analogy below concerning the Crown of Thorns starfish, and how inference and a lack of accurate quantification can result in inappropriate policy.(2) consider direct observation and quantification - Quantify the delta water temperature that anthropogenic global warming contributed to the recent coral bleaching events, "on top of" El Nino factors: (A) 2 degC (B) 1 degC (C) 0.1 degC (D) 0.01 degC (E) unknown. Consider the complexity of answering this question by inference with respect to our current knowledge of how much humans contribte to observed global warming, ocean heating and mixing, the heat content and it's relationship to water temperature, and how this might logically impact on water temperature during coral bleaching events.

As I know you are not expert in thermodynamics, I don't expect you to fully comprehend what I am saying here. But don't worry, I am learning to not have high expectations.

PS. Regarding the assumption coral bleaching events are historically unprecedented, I am not the only one suggesting there is potential for doubt. From the Australia Institute of Marine Science http://coral.aims.gov.au/info/bleaching-environment.jsp “The 1997-98 El Niño event was the most extreme in recorded history yet it is still possible that this and the two other major events in the past two decades (1981-82 and 2001-02) were exacerbated by other, slower, climatic cycles which are part of the natural variability of the Earth’s climate and not a response to greenhouse warming.”

So there may be evidence that coral bleaching has been worsening over the last century, but that does not mean what we are observing is not common on millennial timescales. That perhaps may go some way to resolving the relevance of Sou's questions: How did the reefs manage to survive? How is it that there's no sign of these frequent mass coral bleaching events? How did all the fishers miss it? How did the seas get so hot without any impact on land or in the ocean that left a sign? What caused these extra hot spells in the ocean?

Brian wrote: "Sou, let me explain this one more time. In your post above, and in your article, you assume that it is a FACT that current coral bleaching is (a) related to global warming, and therefore escalating in severity and intensity, and (b) that this will ultimately destroy the GBR."...and more repetition.

Read the article again, Brian. Then, read each comment again. Then go away and read up about a) global warming and b) coral reefs. Then read a critical thinking text and think about why what you wrote is inaccurate. Look up the words "you", "assume", "will" - to start with. Also, think about, but don't come back and tell us, where in the article above you got your b) from.

Oh,and before you explain "one more time" again, don't. You've done it umpteen times already and in doing so, shown no sign of properly comprehending the science, the HW article, or any of the replies to your comments.

I think I see what BW is saying. The paper should have had a control planet with a GBR and subjected it to global warming until the reef was dead. Then the authors should jump into their time machine to the present on earth and presented their paper with irrefutable evidence that GW kills reefs. Then this paper could cite that paper and all would be well.

Brian Westlake, there's a very simple way to resolve your claims. Put them to TerryHughes, or to OveHoegh-Guldberg, or to Charlie (John) Veron, or to any of a number of other researchers. These people are all very approachable and more than happy to discuss the science of coral bleaching and reef decline, and the bonus is that you can have public discussions with comments that comes straight from the horses' mouths.

Please let us know how your conversations progress, and what insight you gain from putting your thoughts straight to the professionals who know more about the science than anyone else.

Jammy and Bernard, still missing the point. I have no issues with the scientific conclusion,supported by the experts in the field, that coral bleaching is primarily caused by heat stress. The problem is that the author of the article above, and some of the authors of referenced papers, all infer that AGW contributes significantly to the cause of this heat stress without suitable reference to quantification of that contribution. eg Hughes21 bases all such assertions to [25] van Hooidonk, R. et al. which actually does not conclude on the issue of AGW and quantifying ocean heating.

This whole thread is about demonstrating and QUANTIFYING increased water temperature connected to AGW. The article, and papers were devoid of suitable references demonstrating that correlation. It is INFERRED that the 2016 bleaching is correlated to unprecedented global warming, eg [Sou] "There have been El Ninos for centuries and it's only in recent times that they've heated up the oceans so much that they've caused mass bleaching." is a statement that has no reference attached - it is purely an inference, with scant observational evidence. I acknowledge it is completely logical, and probably correct. But it should be called out that it is an inference and not demonstrated by observation. If you don't do the science right, you leave yourself open to rogues like Jim Steele.

And if you think I am a climate science denier, you are not paying attention.

You now want a "quantification of that contribution". That's called "shifting the goal posts". Previously you implied there was no contribution, so I guess that's progress.

The best estimate of the contribution of human activity in the latest IPCC report (which is a bit old now) was that humans have caused all the warming since the 1950s, (and some prior to that).

From the report:It is extremely likely that more than half of the observed increase in global average surface temperature from 1951 to 2010 was caused by the anthropogenic increase in greenhouse gas concentrations and other anthropogenic forcings together. The best estimate of the human induced contribution to warming is similar to the observed warming over this period.

Next goal post shift - I mean, next question?

As for you insisting I and scientists use the word "inferred", whether in a blog article, a comment, or a scientific paper - go jump. Do you demand that of yourself? No. Do you demand that of every scientific paper that you read (if you have ever read one, that is)? No. Have you ever demanded that of any denier blog writer? I doubt it. Do you know what you're talking about? Based on the evidence here, I infer not.

Read the comments from jgnfld for once, and read the references he gave you. Try to understand them if it's possible. Quit pretending you know more than real scientists. Lastly, if you think the reefs have been hit by as many mass bleachings in the past in as short a time period as a result of hot oceans, tell us all when that was, what happened to the reefs as a result, how the seas got so hot, and on what evidence you base your assertion.

PS This blog provides more references than most. Brian wants to set the bar even higher. If he'd looked at the second comment above, he'd have found I referenced work that reported only about three mass bleaching events over the 103 years prior to the 1970s or so. Lots since.

That's not enough for Brian, yet he has not come up anything to refute this research, nor has he done any research himself (based on the evidence).

Brian Westlake, I simply say again - take your protestations to the people on the front line.

If you don't perhaps I should do it for you. It wouldn't be the first time I've taken something to the relevant experts in the field on behalf of a troll who's not had the courage to do so themselves. And to date I've never had a troll supported by the answers I've received.

So now you have resorted to lying. Do you have a quote to support your claim?

Sou: "The best estimate of the contribution of human activity in the latest IPCC report (which is a bit old now) was that humans have caused all the warming since the 1950s"

Um, according to your reference, I think you mean half the 0.8 degC warming of the atmosphere (not ocean) this century, right?

But this actually doesn't provide any quantification of the actual contribution to water temperature on reefs. Is it 0.4 degC? Is it more? Is it less? Is the amount of warming relevant compared to other factors? None of these issues are discussed above, none are referenced, and yet these are the questions that are relevant to your inferences.

Lying, really? Perhaps you've forgotten how you started out, Brian. This is from your first comment:

Your immediate connection between global warming and the El Nino related coral bleaching events in 1982, 1998, 2002 and 2016, is an assumption, and not one that is immediately supported by scientific evidence. ... Also the unprecedented heating of tropical water is certainly caused by El Nino events, though not necessarily “on top of global warming”. ... It is important to note that neither the low sea level, higher water temperature nor drought are necessarily associated with anthropogenic global warming.

Bernard, you appear to be assuming that experts in marine biology also have expertise in climate science.

Like you, I am not shy about going to the experts. I recall exchanging some interesting emails with Mario Molina some 20 years ago. He assisted me in better understanding the chemistry of polar stratospheric ozone depletion. Yet he was unable to address my fundamental concerns about the biological implications, because it was not his area of specialty.

Um, according to your reference, I think you mean half the 0.8 degC warming of the atmosphere (not ocean) this century, right?

Nope. The IPCC was referring to surface warming and said that the best estimate is all the warming since the 1950s was from human activity. (Read the quote again.)

As for you wanting the researchers to put a number on human contribution to the ocean temperature (compared to El Nino), that's asking for something different from what their research was about. (There have been estimates at the global level, but not local AFAIK.)

Frankly, it's been obvious from the outset that you don't understand the first thing about this research. It's not an average temperature that causes bleaching. It's the time spent above a tolerance threshold. This is likely to happen more often in coming years as global warming increases.

I can tell you don't care about that. You just want to fight about something. You don't care what. Take whatever grief you're nursing (which has nought to do with corals or science) to your local boxing ring. That'll be much more satisfying, for all of us.

Brian, your issue of quantification was not "fundamental" - it's a goal post shift and not a relevant one at that. You first ignorantly raised "quantification" only today, not a week and umpteen of your comments ago when you got your knickers in a knot and began to insert your science denial here.

Sou: "As for you wanting the researchers to put a number on human contribution to the ocean temperature (compared to El Nino), that's asking for something different from what their research was about. "

Exactly what I have been saying.

"This is likely to happen more often in coming years as global warming increases."

This is an inference, since (as you say) the research you have been quoting does not prove it.

BTW, other scientists have worked out the likelihood of coral sea temperatures being as hot, with and without human caused forcings. From that HW article: there's about a 175 times increase in the likelihood of very hot March months in that region, "because of the human influence on the climate".

Not what Brian was looking for in his new "quantification" demand, but it gives you an idea of what is happening with global warming.

The Townsville Bulletin has printed an article in which they falsely attribute a quote to Terry Hughes, and apparently lied, saying he couldn't be contacted yesterday (when I exchanged emails with him). They also, appallingly, wrote as if Jim Steele, the crank pseudo-scientist, was somehow more credible than all the coral reef experts in the world. (See this from the ABC's MediaWatch.)

Steele seems to base his ambitious claim on Ampou et al, and the Cairns tide gauge, plus tide projections from BOM. He does this while decrying a lack of scepticism and rigor on behalf of Hughes and contributors....irony is dead.As you say, Amou et al. discuss a local event and never offer a total attributional distribution for any mass bleaching event of regional or global extent.The Cairns tide gauge shows,unsurprisingly, that the 2010-11 La Nina was a peak in monthly tide heights and monthly figures have declined a little since then...but really this is irrelevant because it is monthly data, too coarse to support his assertion.

As for the tide projections, indeed there were a couple of low tide clusters amounting to a few days in autumn 2016 that may have had some minor contributory effect to some reef damage, but we do not know what the actual tide figures were compared with projections: local wind and air pressure may have seen higher figures than projected anyway..

It's just ill-willed slipshod speculation from Steele, and sad that the Townsville Bulletin should uncritically fall for it.

It shows a lack of journalistic ethics. It also shows a disregard for facts, and disregard for the well-being of the local community they are meant to serve, all for the sake of faking controversy to get attention.

Townsville Bulletin is owned by News Corp...The article takes the form of so many News Corp anti-science pieces. Elevate a non-expert [David vs Goliath template]to parity with real experts, wheel out contrarian with form, 'teach the controversy' where there is in fact none, and bury the most important evidence for the reality deep in the piece, if you use it at all.Will this be run now in The Australian? Various News Corp professional trolls will no doubt push it in their columns....No one will actually read the Hughes et al paper.Standard News Corp model is now failure of due diligence. There is no downside, Press Council is toothless.

Ha ha, yes, very good jkrideau. Well spotted. What are some of those names?

I ask semi-seriously because it is an issue - which came first, the hypothesis or the data? A lot of hypotheses are made to explain a set of data. Take Kepler's explanation of the data collected about the motions of the planets and his formulation of Kepler's law. When does it cross over into bad scientific method?

Jim Steele actually wrote this utter foolishness: "bleaching without mortality is not a worrisome event no matter how extensive." When corals bleach, they do not eat, they do not grow, they do not reproduce, and they are severely weakened and susceptible to disease. Jim Steele, the bird call and nature hike expert, says that this is not worrisome? Can there be any greater evidence of ignorance and quackery than Jim Steele's fiction to pretend that global warming is not real? Unreal.

In response to your challenge for correction of this article “All errors are mine - so if you see some, let me know and I'll correct them”:

The thrust of your article, that recent coral bleaching events were caused almost entirely by heat stress, is well presented from the available science. However you state: “The causes of the present-day demise of coral reefs are varied. One of the biggest causes is global warming. This is having both direct and indirect effects on coral reefs.” Your immediate connection between global warming and the El Nino related coral bleaching events in 1982, 1998, 2002 and 2016, is an assumption, and not one that is immediately supported by scientific evidence. It may be logically inferred that as global warming occurs, there will be increased coral bleaching, but this is not directly observed, and the connection is anecdotal at best. The history of direct observation and measurement of coral bleaching is only about 30 years, and there is no clear way to observe the degree of coral bleaching going back in time, plus there have been too few events to establish a link. We do not know how common coral bleaching events are over century or millennial timescales. Also the unprecedented heating of tropical water is certainly caused by El Nino events, though not necessarily “on top of global warming”. From the Australia Institute of Marine Science http://coral.aims.gov.au/info/bleaching-environment.jsp “The 1997-98 El Niño event was the most extreme in recorded history yet it is still possible that this and the two other major events in the past two decades (1981-82 and 2001-02) were exacerbated by other, slower, climatic cycles which are part of the natural variability of the Earth’s climate and not a response to greenhouse warming.” Whilst there is no doubt the subsequent 2016 event is unprecedented in the short history of observation, there has been no evidence to suggest that the circumstances of the El Nino event was not similar to the 3 previous events, and the result of natural factors. Also in reference to Peter Ridd’s comment, you state ” Low sea level was considered a likely a factor with the mangrove die-off, but so was unprecedented high temperature and severe drought. Global warming again!)” It is important to note that neither the low sea level, higher water temperature nor drought are necessarily associated with anthropogenic global warming.

Brian, I get that you don't "believe" scientific evidence. Your faith that global warming will stop or won't continue to damage corals is hardly admirable. Do you really want to kill off coral reefs and fisheries as soon as you can? Perhaps because you can't stand the thought of modernising the energy sector. (Yep, I remember your comments on energy here that you've made before. You're a fan of outmoded dirty power.)

Your wanting to cling to the 'not impossible' is not touching (though "touched" is a word that your comment brings to mind).

BTW - because you claimed: "It may be logically inferred that as global warming occurs, there will be increased coral bleaching, but this is not directly observed, and the connection is anecdotal at best.", it's "possible" that you missed this part of the article you quoted from.

We have already entered the time-frame where mass bleaching is occurring without El Niño enhancement. If the relationship of atmospheric CO2 levels to the amount and/or frequency of bleaching continues on its present trajectory, there will be a point where every year will have a similar impact on corals as the worst El Niño events have had in the past.

http://coral.aims.gov.au/info/bleaching-environment.jsp

I can't be bothered with the rest of what you wrote. People who want to learn will read the article and the references above as a starting point. They'll be more interested in science, facts and evidence than the denial of some obscure denier commenter who's strayed out of his comfort zone (and who's not too different from Malcolm Roberts in his cherry-picking and argument by assertion).

@-Brian"It may be logically inferred that as global warming occurs, there will be increased coral bleaching, but this is not directly observed, and the connection is anecdotal at best. The history of direct observation and measurement of coral bleaching is only about 30 years, and there is no clear way to observe the degree of coral bleaching going back in time, plus there have been too few events to establish a link. We do not know how common coral bleaching events are over century or millennial timescales."

Wrong.Coral forms growth-rings, rather like trees. It also incorporates different ratios of Oxygen, Calcium and Strontium isotopes in response to sea surface temperature and salinity changes. So there is a long and extensive record of past climate, and the slower growth associated with bleaching from coral cores.

I get that you didn’t understand my post at all. I never said anything implying “faith that global warming will stop or won't continue to damage corals”. Is it really your MO to smear and lie about people when they disagree with a minor point in your articles. Why do you feel the need to do that?

Your quote from AIMS is exactly what I mean by “logically inferred”. And I have no problem with that. I am merely pointing out that this is what you are doing when you reach conclusions about global warming and coral damage, and that the connection is only logically inferred, and not directly observed. As a scientist I thought you would want to demonstrate that sort of rigour in your quest against climate denial, to ensure you cannot be attacked by folk with an agenda like Jim Steele.

Izen, your counter reference does not make any reference to coral bleaching. Certainly AIMS has identified that current events (4 in a period of 30 years) are unusual over the last century or so. But cores can’t see clearly beyond that timescale, so there are very few data points.

What are you on about, Brian? Coral bleaching is directly observed. The mechanism by which bleaching occurs in extra hot water is well known and based on evidence. You implying it's just "anecdotal" (whatever you think that means) or pie in the sky is ludicrous.

If you think that pointing out your science denial is "smearing", then that's fine by me. (The evidence is there. And sure, there are times that I'll let show my irritation with the anti-science tactics of people like yourself.)

The rigor you're (not) looking for is in the article above as well as in the references, and the work those references reference. I'm not about to spend another few days picking up on each of your wrong insinuations individually.

@-Brian"Izen, your counter reference does not make any reference to coral bleaching."

No, it describes at the layman level how it is detected, as well as all the other data about SSTs and salinity. However a few minutes work with a search engine will produce multiple science papers that deal with exactly that issue, ie;

Sou, yet again you apply inference rather than referencing observation to make your case. It is clear you don't understand the difference, and you don't want to.

Izen, how far into the past do natans provide information? 100 years? What is the accuracy for >100years, your reference does not say. I say again, too few data points to say that current coral bleaching events are unusual on the time-scale of a typical coral reefs existence. There is no direct observation that bleaching correlates with greenhouse warming, nor that bleaching is a portent of doom for reefs in the long term. Such claims are inferred only, and this should be clearly stated when making claims, not assumed as fact.

@-Brian"Izen, how far into the past do natans provide information? 100 years? What is the accuracy for >100years, your reference does not say. I say again, too few data points to say that current coral bleaching events are unusual on the time-scale of a typical coral reefs existence."

You can say it repeatedly without affecting its inherent inaccuracy. An error you could correct with a few minutes search engine use which would reveal hundreds of papers researching the very 'questions' you rhetorically ask. The reliability and sensitivity of corals to sea temperature and a multitude of other factors is extensively studied.

From this we know what the past El Nino cycle, and regional variations have been. Here is an example, but you do need to consider why you have been ignorant of this fact until now.

http://journals.sagepub.com/doi/abs/10.1191/0959683603hl606rpEight, multicentury, Porites coral cores were used to develop a 373-year chronology by cross-dating techniques adapted from dendrochronology.Characteristic patterns of distinct luminescent lines within the coral skeletons were matched between coral cores from inshore and mid-shelf reefs in the central Great Barrier Reef, Australia. Skeleton-plots of luminescent banding were produced for each core and combined into a master chronology back to ad 1615.

Izen, your few minutes of search engine use has revealed nothing of relevance, despite your bluster. Your reference is measuring rainfall and thereby ENSO oscillations. Nothing to do with coral bleaching, which is a specific short-term event, highly variable across geography and climatic cycles, and so far more difficult to accurately discern from coral cores.

@-Brian"Izen, your few minutes of search engine use has revealed nothing of relevance, despite your bluster."

I suspect in this case relevance is in the eye of the beholder.

My brief experience in searching for papers published on this subject indicates there are hundreds of papers specifically researching the very factors of variability across geography and climatic cycles, as well as species differences. A paper like this:-http://www.biogeosciences.net/12/5677/2015/bg-12-5677-2015.pdfDoes not indicate to me that this is a subject where knowledge is undeveloped or fragmentary and uncertain.YMMV

@-"Your reference is measuring rainfall and thereby ENSO oscillations. Nothing to do with coral bleaching,..."

It was selected to answer your claim that there is no accurate long term climate record derived from coral. Actually the banding and rainfall effects ARE indications of bleaching events, although you did perhaps have to follow up the citations and references given for how and why...

https://link.springer.com/article/10.1007/s00338-003-0304-7"Two hiatuses in coral skeleton growth, associated tissue death and subsequent regrowth, were discovered while dating eight multi-century Porites coral cores collected from the central Great Barrier Reef (GBR), Australia. ... Intense luminescence observed in corals growing continuously during the 1817 event suggests that low salinity from river runoff was a contributing factor, analogous environmental conditions to those that were associated with the 1998 bleaching event in the GBR."

There are measurable increases in ocean temperatures and atmospheric humidity that have formed a higher baseline from which recent ENSO events have developed. As a result the peak ocean temperatures and rainfall are higher for recent events than for any in the last few thousand years. A fact confirmed by the coral core O18 and Ca-Sr ratios.

But I apologies for any bluster and would concede that how relevant you might think this body of knowledge to the credibility of the current warnings of a rapid coral die-off globally from the 2016 EL Nino after ~20years of a marked decline in coral growth may depend on your acceptance of mainstream scientific evidence.

Brian wrote in his main comment above: "Your immediate connection between global warming and the El Nino related coral bleaching events in 1982, 1998, 2002 and 2016, is an assumption, and not one that is immediately supported by scientific evidence."

While I said I wouldn't pick up on everything you wrote, Brian, let me also point out that I didn't mention 1982. The other years I did write about the evidence provided in the Nature paper. There's lots more evidence in the literature and elsewhere. Coral bleaching in some of those hot ENSO years really and truly happened.

Thing is, I mentioned global warming early in the article, however any "connection" in the HW article between global warming and ENSO was far from immediate. It is quite a way down in the article. Nor can I take credit. I was reporting the "connection" made by scientists.

El Nino is not a necessary factor. The necessary factor for heat-related bleaching is extremely hot seas where the coral lives. The 2017 bleaching event is not associated with an El Nino - just with hot seas.

Then you strangely wrote two inconsistent things:

"unprecedented heating of tropical water is certainly caused by El Nino events, though not necessarily “on top of global warming”."

And, you also wrote, in reference to 2016: "there has been no evidence to suggest that the circumstances of the El Nino event was not similar to the 3 previous events".

Here I'm wondering what you are thinking. It's all topsy turvy especially when combined with your statement about coral bleaching, global warming and El Nino I quoted up top. The evidence was put in front of you in the HW article and the paper in Nature. 2016 was the worst mass coral bleaching event ever, meaning worse than the others. The "circumstances" of a big El Nino "on top of global warming" meant 2016 was the hottest year on record. The seas the corals reside in got extra hot which caused the corals to spit out the algae they coexist with, and turn white. I don't know how you missed the text and charts above.

Evidence shows that ENSO years (both El Nino and La Nina) are hotter than previous ones as the world heats up. That's what I meant by "on top of". (All weather is affected by global warming of course.) If you want to try to dispute that El Nino and La Nina and neutral years are getting hotter, you'll have a really hard time getting anyone (except hard core deniers) to believe you. The bigger point is that the seas where the coral lives (and were bleached) were much hotter in 2016 over larger areas than in previous mass bleachings.

(I'm wondering if Brian thinks that the GBR is in a NINO region. It's not. Heat travels when it's released in an El Nino, plus seas can get hotter with global warming.)

Oh, and "unprecedented high temperature" is most definitely associated with global warming. Warming = higher temperatures.

All I am doing is suggesting that it is wise to speak in the careful language of science, and I get Sou's sexist and ageist abuse and continued demands that logical inference without direct observation still equates to scientific fact, and Twinotters idiotic name-calling and accusations of logical fallacies that he apparently does not understand.

The logical inference is that Brian doesn't accept direct observation, or know what logical inference entails. (Logical inference also leads one to the conclusion that Brian is learning the art of concern trolling.)

"The logical inference is that Brian doesn't accept direct observation, or know what logical inference entails."

The inference I took was that Brian was deliberately attempting to mislead by what he mistakenly thought was clever use of semantics. That leads to other inferences, but as they are about Brian's character they are neither interesting or worth bothering with.

"All I am doing is suggesting that it is wise to speak in the careful language of science,"

As in implying that temps are flat and only go up or down as a result of various cycles? There is this "scientific" thing called the greenhouse effect which really is causing a trend on top of any cycles, you know!

Brian, you wouldn't know the "careful language of science" if it reached up and slapped you in the face for your abuse of it.

I'm always intrigued/appalled by deniers who talk about and lecture practicing professionals about "science" and the "scientific method" with an apparent grade school understanding of scientific induction.

@-Brian" ...and continued demands that logical inference without direct observation still equates to scientific fact, "

Its de ja vue all over again.Y.B.

I am reminded why I seldon engage in this science ping-pong thesedays. But your blantant misstatement that we know little about how coral responds to climate conditions beyond the last 30 years of observation was... triggering. (grin)Particularly as coral has been extensively studied to elicit its response and has provided one of the best sources we have for the poast climate. Especially of ocean temperatures, salinity, pH, turbidty, nutrient levels etc. Surveying dead reefs above sea level or sumberged deep gives the dates and rates of sea level rise.

In times long past when discussing Evolution with Creationists there would often come a point when faced with the overwhelming volume of scientific knowledge that mankind had established in 150 years of research, the Creationist would fall back onto epistomology.

They would attempt to dismiss or at least diminish the validity of knowledge gained by logical inference from known physics, chemistry and biological processes and proxy indicators. (fossils DNA) against direct observation.'The origin of species and common ancestry has never been DIRECTLY observed, MERELY derived from inference.' Would be the assertion, with the follow up that therefore it was uncertain, (gaps, missing links) and can be rejected as lacking the legitimacy of direct observations.

It was usually sufficient to point out that they could not claim to have made any direct observation of their own origin. But I hope we could agree that with the logical inference from our knowledge of biological reproduction, and the proxy indicators of the DNA, the similarities, and differences between their parents and their own DNA, would allow us both to be certain, with at least equal credibility with direct observation, that their origin was as a simple single cell that developed as a result of a reproductive act by their ancestors.

It might be raised that the parents could provide direct observation, confirming it more strongly. However such sources have proven unreliable, (Storks, gooseberry bushes) and genetic screening indicates that in about 10% of cases one observer is wrong.

Alternative processes, spontaneous generation, is both unobserved and has no credible biological mechanism. One case of parthenogenesis was reported around 2000 years ago. But while it is widely believed, it is dubious and anecdotal.

Knowledge we derive from indirect inference is as valid as observation, or the knowledge of our parentage.

Seriously? Pulling the argument from authority card? Are you a coral scientist, Brian? An applied degree in whatever doesn't mean a lot if you're wrong, especially about a topic you obviously aren't familiar with.

I'm implying using your own words where you state it is unclear whether SST rises and consequent bleaching events are a consequence of greenhouse gas warming but rather may be merely cyclic. If they are a straw man, then the fault is your own.

However, it appears you don't know what a straw man even is. Google "Rationalwiki straw man".

Yes I do have a PhD. I highly suspect yours is engineering or related nonresearch discipline from the hints you've provided. Especially your (mis)statements about scientific induction and observation. See "Salem hypothesis" in the same Rationalwiki mentioned above for more information.

In defence of engineers, it is generally only those engineers who have made of career of trashing the environment who - for obvious reasons - take the position that the environment is there to be trashed. Once they have taken that position there is no alternative for them but to become increasingly ridiculous when the issue is examined. And so WUWT becomes a welcome haven for them.

izen, I never said "we know little about how coral responds to climate conditions beyond the last 30 years of observation " Yet another strawman. To be clear I was referring ONLY to coral bleaching, and pointing out the obvious fact that we have very little historical observations of mass bleaching. We therefore need to be careful about making categorical statements from inferred logic, it is sloppy and leaves you open to attack. That is my point, nothing else.

Evolution is directly observed. It is called the fossil record. Evolution is a scientific fact.

The notion of "survival of the fittest" as proposed in Darwin's The Origin of the Species is a theory arising from inferred logic. It is a valuable theory, but it is NOT A FACT. It is a theory. It is important to acknowledge this, but you (and Sou and others here) seem disinterested in acknowledging this distinction.

No Sou, I am not the one with the "argument by authority", I was not that one who made an ad hominem comment about "apparent grade school understanding of scientific induction."

Then I note you and all you your silly followers proceed with more "argument from authority", something about how scientists are better than engineers (for some reason), and even that engineers are evil (really?).

FYI I have a degree covering chemistry, physics, thermodynamics, fluid dynamics, and environmental science. Yet apparently I am not qualified to make a simple and obvious statement that an inferred conclusion is not a fact, and should not be assumed as fact.

Uh Brian...Possibly you missed this in engineering school, but gravity is an inference. In fact it is probably more poorly understood at a fundamental level than global warming. So is this weird idea that those twinkly points of light in the sky are massive balls of hydrogen at immense distances powered by a process called "fusion". Interestingly spectroscopy, which underlies this inference, is the same science which underlies the greenhouse effect.

Science works by erecting now rather immense chains of inference that all interlock. Even the hardest experimental setup requires that one ASSUME that all relevant variables have been controlled for when a difference is observed in order to make any (inferred) conclusion. However when thousands of scientists independently test that assumption in myriad related ways over a long period of time, well that inference gets accepted and incorporated.

Stick with your area of real expertise and listen to the real experts about their areas of expertise when you are not within it. Scientists will never, or at least should never, lecture you on fundamental engineering principles.

By the way, ALL science is "argument by authority". Competent, well and truly tested, and broadly recognized authority, true. But argument by authority nonetheless. That is how scientific induction works. It really can be no other way. So yes, your demonstrated knowledge of scientific induction is quite low level.

Uh jgnfld, gravity is a phenomenon that is directly observed, and the laws of gravity are a fact, they are observed to act the same everywhere in the universe. That gravity is caused by a distortion in space-time by mass is a theory that is inferred. Newtons law of gravity is theory.

In the same way, in respnsse to your comments previously on Evolution and Creationism (note Twinotter, I did not raise the subject): Evolution is a fact, "survival of the fittest" is a theory.

I never said that there is anything wrong with applying inference, it is a fundamental part of scientific process, along with creation of hypothesis and theory. I never said that something that is inferred or theoretical is necessarily wrong, nor did I say it has no value. Newtons law of gravitation are only a theory, yet we do not jump off buildings because "gravity is just a theory".

My only point here is that if you make an inference, you should call it out, since there is room for an alternative hypothesis - inference is not fact.

Whilst this thread has gone on some wild tangents, I have not once deviated from my single point which I have now restated ad nauseum. Allow me to make one point of illustration:

In the 1960s and 1970s there were observations of large-scale crown of thorns starfish outbreaks on the GBR. Since these were devastating large parts of the reef, and trends were alarming, it was inferred that non-natural influences must be the cause, leading to the theory that humans were the cause, and so a policy that immediate and drastic action was required or the GBR would be destroyed. Since then we have learned that COTS outbreaks are natural and common, and we have better quantified the influence that humans have on the situation, allowing us to react in an appropriate way to the COTS threat.

I am hoping you can see the parallel, and the importance of scientific accuracy in forming good policy. i.e. knowing what is fact, and what is inferred, is important.

Brian, don't be so coy. Since you obviously think you have a better "alternative hypothesis" to explain the mass bleaching events reported in Hughes17, which you've inferred from your rigorous and extensive analysis of the data plus your deep knowledge of the mechanism of coral bleaching, come out with it. Better yet, get it published in Nature.

Frankly, I still don't know what Brian's going on about. Mass bleachings occurred and the Nature paper attributes it with periods of extra hot water. The paper provides data to support that conclusion. That's what the HW article reports. (The fact that corals bleach in hot water is well-documented. There's nothing new in that. The fact that seas will get hotter as the world warms is self-evident. There's nothing debatable about that.)

What I infer is that Brian came here looking for a fight, so he made one up. Or maybe he just felt his nearest and dearest weren't giving him attention he yearned, so he chose to troll for some attention here. Or maybe it's as simple as his confirmation bias is showing.

Re. "knowing what is fact and what is inferred" your lack of knowledge about induction/inference is showing.

When you read a thermometer, or even feel hot or cold, are you observing a "fact"? Or are you inferring that a theoretical concept, heat, has a certain value? What you observe is a certain electrical potential in a thermocouple, or the height of a liquid in a marked column, or the expansion of a bimetallic coil, or certain physiological sensations and changes, etc. Not "real" heat.

Hell, the color purple is an inference your brain makes automagically. It does not even exist as a "real" spectral color as Newton showed long ago. It is an inference. BTW, one underlying point of all illusion research is that your senses do not report "facts". They report a synthesized model of the world.

There are near and far inferences. There are good and bad inferences. There are more supported and less supported inferences. But you are confused about all this at anything other than the most simplistic and elementary black and white level (well black and white is a mental construction as well as is easy to show in illusion research--google "Adelson illusion"). That is not "name calling", that is, well, er, an observable fact.

Sou, no data is presented in the paper to attribute coral bleaching to global warming. Several inferences and assumptions are made (a I have said this is sloppy science). But no data is presented to prove that case. People can see that for themselves.

First you said that I was wrong and wrongly claimed "Hughes17 does not attribute...".

Now you, who have not shown any scientific expertise let alone in coral science, are saying the work of career experts, published in Nature, was "sloppy". And all this without producing any evidence whatsoever to support your claim. You don't even say what part you found "sloppy". (You've shifted from me to the authors whose work I reported now. Not all the papers though. Is Ampou17 sloppy? What about Leggat06?)

Look at the charts in the HW article above if you can't be bothered looking at the paper. They show that the sea temperature was quite extreme - which is why corals bleached. (Look at 2016 data for the worst example.)

Again: No data is presented in the paper to attribute coral bleaching to global warming. Several inferences and assumptions are made. But that's OK, there is no problem at all in making unsubstantiated inferences in a scientific paper.

Sou, you spend a lot of time trying to characterise me as a climate science denier. I am not. Your persistence in this matter is disturbing.

There is a lot of data and analysis in the paper showing that hotter seas were what led to those episodes of coral bleaching, plus references to other work showing the impact of global warming on corals. (Learn how to read a scientific paper.)

Their focus was on analysis of temperature (as degree heating weeks) vs other potential causes of the mass bleaching. (There is a word limit.) They know that most of their readers understand that global warming means hotter seas. The authors assume readers aren't idiots. They didn't count on people like yourself trying to work through the paper (which you still haven't managed to do properly).

Like I said, you wouldn't believe a paper about antibiotics unless it also had data that showed from first principles that germs exist.

You are essentially denying global warming exists, Brian. You started denying it in your very first comment at 4:26 pm. Even in this latest comment you talk about "unsubstantiated inferences", when their data showed the hot seas very clearly. Why do you deny you've been denying global warming? Then you ducked and weaved and wrote some nonsense about inference, which you don't understand.

Now you're just writing the same old comments for the sake of it or to see it on the internet or something. If you've got something new to say, say it. If you want to admit your errors, admit them. If you've not got anything new to add, don't say anything.

Sou, anyone reading the above thread can see that I have only ever made one simple point, which is succinctly summarised here. I have not once denied climate science. Nor have I stated any beliefs about "germs". The majority of contributions thread have been you and others making absurd and unsubstantiated claims about who I am, and what I believe, most of which is spectacularly wrong, but I couldn't be bothered arguing. I think this thread is worthy of your website.

Got it, Brian. Thank for the link on "fact" and the different types of inference. Not quite as deep as the links you were provided, but it'll do as an approximation.

You're complaining the equivalent of the fact that I didn't categorically prove as hard fact that the sun would rise tomorrow (or that it rose on a daily basis a million years ago) and I should have stated quite explicitly that one can "only" infer it.

Okay - here goes. It is not 100% certain that the sun will rise tomorrow. Ask Brian, the scientific expert in all things, what he believes will happen in the morning before you make any plans.

"The flaw in the global warming argument is they have been unable to categorically link CO2 to increased temperatures. Whilst CO2 is increasing and we can't dispute that, the correlation with warming has not been demonstrated in these models let alone if the effects are lineal or not.

Well I did say more than once that it was a simple and fundamental point that I was making. The tedium that followed resulted from the inexplicable need for some to argue this simple point. At length. And with a significant amount of invective. Tedious and humourless indeed.

Science 101 is often wrong in terms of any professional understanding of issues. This is particularly true WRT the sophomoric belief that the hypothetico-deductive method as described in first year survey texts has any real bearing on how professional science is actually performed.

@-Brian"To be clear I was referring ONLY to coral bleaching, and pointing out the obvious fact that we have very little historical observations of mass bleaching."

From which we can infer that it happened very little in the past. Certainly on nothing like the scale we are seeing now. Whenever scientists core coral to determine the facts about past climate they would find the narrow or missing growth rings of bleaching, if it has occurred. As I showed you in a previous link, a survey of the GBR found 2 episodes of die-back and regrowth, both very limited in the region surveyed, affecting just one core in eight. If they repeated that survey at present most of the reef area they surveyed then is bleached, and a significant proportion is dead.

@-" Yet apparently I am not qualified to make a simple and obvious statement that an inferred conclusion is not a fact, and should not be assumed as fact."

Is this simple and obvious statement a fact, or do you infer it from observation ?

We can do no such thing. "No evidence" is not "evidence of nothing". Your argument is based on assumptions and observational data that provides increasing inaccurate data beyond 100 years in the past. We simply do not have enough data points to draw conclusions about the relative severity and frequency of recent events. That such events are becoming more common and severe is inferred.

I suppose, then, you also assert that the fact there is no evidence in growth rings that the Sun didn't just go out and fail to shine for a summer or two in the past 500 years is not evidence that nothing of a kind occurred?

Singular bits of no evidence can provide limited or no basis for arguing that there is evidence of nothing, true. However a pattern of no evidence from multiple lines or from a particularly strong single source of no evidence can indeed provide a sufficient basis to infer that nothing happened.

This is what I mean when I say your scientific induction skills are elementary. Why it's almost like you memorized some definitions off a foundation, first year science course handout!

I was once a member of a cultural society (which shall remain nameless) where, in our local branch, was a member who was superlatively good at just about all of the many skills and areas that were fostered by the organisation. The trouble was, he did not exist. Everything that he accomplished was actually the efforts of a rather clever group of individuals who were making the point that it was political connection and reputation that earned award and favour in such organisations.

Going to national events was always amusing. Out-of-towners and interstaters would always ask where (let's say 'John') was, and the in crowd would say "oh, you've just missed him", or "he's meeting with so-and-so", or some other vague response. Consequently the existence of 'John' was cemented in the minds of many who never actually met him, but were convinced that he had a physical presence and that thye'd been in it.

In hindsight the exercise would present an absolutely fascinating study in both the psychology of reputation, and the flaws in reward mechanisms in nepotistic structures. I'm long out of that scene though, and I suspect that 'John' has mysteriously vanished into history as well as he was able to vanish around corners at particular events.

And a post of this nature would be remiss if it didn't tip the hat at the Dread Pirate Roberts...

As for the troll here, it might be of interest that his handle can be anagramed to:

No. Its about discussing the anti-science of the climate change denial industry set up by Wayne Tracker and his pals.

And when the opportunity arises we get to take the piss out of climate change deniers. If all the most prestigious scientific organisations on this planet cannot convince you of the reality of climate science then there's little point us trying.

Also:Wartlike 'n' baseLast weak brainWet brain leaksWeak brainletsA brat knew liesAble ink-waster (metaphorically)Bestial wankerIt was worth pointing out his ignorance a few times for the sake of any readers who might think he had a point, but I don't think there's any reason to continue.Nail berk? Waste.

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All you need to know about WUWT

WUWT insider Willis Eschenbach tells you all you need to know about Anthony Watts and his blog, WattsUpWithThat (WUWT). As part of his scathing commentary, Wondering Willis accuses Anthony Watts of being clueless about the blog articles he posts. To paraphrase:

Even if Anthony had a year to analyze and dissect each piece...(he couldn't tell if it would)... stand the harsh light of public exposure.

Definition of Denier (Oxford): A person who denies something, especially someone who refuses to admit the truth of a concept or proposition that is supported by the majority of scientific or historical evidence.
‘a prominent denier of global warming’
‘a climate change denier’

Alternative definition: A former French coin, equal to one twelfth of a Sou, which was withdrawn in the 19th century. Oxford. (The denier has since resurfaced with reduced value.)